| Abstract |
A three-dimensional subsidence modelling method is described here based on linking two computer codes: Tough2 and Abaqus. Tough2 is a well-established finite volume code for simulating complex multi-phase multi-component sub-surface flows. It is widely used for geothermal reservoir modelling. Abaqus is a general purpose finite element package that can be used for solving geotechnical problems. It can handle three-dimensional problems for heterogeneous materials with very general and complex constitutive properties. The pressure drop data available from the finite volume Tough2 model is converted into a body force distribution that causes deformation of the soil/rock structure. It is then interpolated on to the finite element mesh used for the Abaqus rock mechanics calculation, which provides the surface deformation or subsidence. The conversion process between the two computational grids uses a least squares finite element method with smoothing to interpolate the pressure data from block centres in the Tough2 model to element vertices in the Abaqus model. This process allows for the Abaqus grid to be finer than the Tough2 grid. Results are presented for a simple test problem. |